Comment Re:Goodbye (Score 4, Insightful) 74
Except not to you. You're confusing data minimization (the website doesn't get your name from the token) with unlinkability (nobody can connect your activity to your identity). The *token itself* doesn't reveal your identity, but it leaks data in a wide variety of ways.
Even if you browse via a proxy, if the authorization service gets a token directly from your phone, it has now correlated your phone with your proxy-browsed history. A very common means to do secure authentication these days is SIM-based wireless PKI, wheren it has now connected you to your phone number. To governments, it offers a broad range of brand new vectors to correlate you to an identity if you, say, mention you had an abortion or criticize your local strongman leader, since they control the backend infrastructure that establishes the connection between the token and the identity. And not just at signup time every real-world digital credential must be able to be revoked if the phone is lost or stolen, or credentials expire or are revoked. So how does how does the open-source app prove a credential is still valid without "phoning home"? If the app checks a revocation status list, then ISPs, CDNs, or state security services can correlate the exact millisecond of queries to the revocation server with the submission of a verification token to a platform - each time it's submitted. Assuming that they can't just get it with more direct means than timing attacks.
Also, you cannot just "read the code". The frontend is open source, but what is being done on the backend is not. You have no clue what logging polciies, database schemas, operational security, etc the "designated national issuers" or servers handling the credential revocation are using, and what government intrusion has been forced on them. I'd feel a more comfortable if it were all happening from Brussels but handing it over to individual states, some of which at any given point will be authoritarian, is just handing them an easy new vector to unmask people.
As for your "Such systems are implemented in many different ways by member states for other purposes already." - yes, for filing taxes, healthcare, online baking, etc - things that you intend to do and must do under your legal identity. Not for anonymous conversations on the internet. Your argument basically reverts to "But people already do things non-anoymously on the internet , which reinforces my point that yes, this taking something from the "anonymous" category and putting it into the "easily unmasked" category.
If you think this won't be abused, I cannot help you. Not even just abused from a criminal or extrajudicial perspective, but even from a civil one, because orders to unmask someone can be subpoenaed.